This invention relates generally to a balloon catheter having an infusion section distal of the balloon. It is a single lumen catheter. The form of the catheter is such that it may used variously in procedures such as percutaneous transluminal angioplasty (PTA) procedures but is sufficiently flexible in its construction that it may be used for other diagnostic and treatment indications. This balloon catheter is especially useful for isolating a region of the vasculature to be treated and providing a measure of fluid to a limited region distal of the balloon. Because of the presence of only a single balloon region, it is significantly more flexible than other multiple balloon designs and is more readily controlled.
For instance, in percutaneous transluminal catheter angioplasty (PTCA) procedures, a guiding catheter often with a preshaped tip is introduced into the vasculature of a patient. The catheter is initially placed into the human body at a convenient site such as the femoral artery in the groin. The catheter is then advanced throughout the trunk of the body and up into the aortic arch near the heart. Once in that region, the catheter is twisted or torqued from the proximal end so that the preshaped distal tip of the guiding catheter has engaged the ostium of a desired coronary artery. A balloon-bearing catheter is then advanced through the guided catheter, out its distal tip until the balloon on the distal extremity of the dilatation catheter extends across the region to be dilated, and the balloon is then expanded. Expansion of the balloon is typically to a predetermined size and is dictated by the design of the balloon. Often a radio-opaque fluid is used to inflate the balloon a relatively high pressure so to permit the inflation to be observed. Upon completion of the procedure, the balloon is then deflated so that the dilation catheter may be removed and blood flow resume from the thus treated artery. In some instances it may desirable to introduce some amount of a medicament distally of the balloon.
In other procedures, a balloon-bearing catheter typically with somewhat smaller diameter than a catheter used in PTA or PCTA might be used. Generally, the procedure might be considered to be similar to those procedures in that a comparatively larger more guiding catheter is initially placed so that its distal end is near the site to be treated or diagnosed. A balloon catheter, perhaps with a guidewire extending through an existing central lumen, is then extended from the distal end of the guiding catheter to the desired treatment site. The balloon is then expanded and once the procedure is complete, the balloon deflated and removed from the body. Often, the balloon is of a more compliant nature than of the fixed diameter configuration found in a typical PCTA balloon.
The advent of interventional radiology as a viable alternative in the neurological regions of the body has produced demands on catheterization equipment not faced by demands placed on PCTA devices. The need for significantly smaller diameter devices and devices which have a variable flexibility and yet are able to resist kinking is significant. Further, because the advent of superior catheters for use in interventional radiology, adjunct equipment for treating those very small regions of the vasculature are also in demand.
A dual balloon catheter assembly having an integrated guidewire is shown in U.S. Pat. No. 5,320,604, to Walker, et al. In that device, the balloons are separated by a waist portion including an infusion section. The infusion section has a number of perforations allowing the waist portion to communicate with the single lumen of a catheter shaft. No distal infusion section is found in the device.
A somewhat basic angioplasty catheter assembly is shown in U.S. Pat. No. 4,646,742, to Packard, et al. The catheter found in Packard et al., in general, is shown to have inner lumen but also an inner tube which may be removed completely for enhanced perfusion or for a replacement with a guidewire. The catheter appears to have but a single distal port, in line with the lumen, from which to perfuse fluids.
A multiple lumen angioplasty balloon catheter having a balloon carried on the distal end of the catheter shaft is shown in U.S. Pat. No. 5,380,282, to Burns. The catheter shown therein includes a distal, radially expandable valve used to limit or block fluid flow between the lumen of the catheter and the patient's body during inflation and deflation of the balloon.
U.S. Pat. No. 5,318,535, to Miraki, describes a low profile, exchangeable, dual lumen perfusion balloon catheter assembly for use in dilatation angioplasty procedures. The outer balloon-bearing member includes infusion ports which are distal of the balloon. That component, however, does not contain any valving apparatus nor does its inner lumen appear to have any communication with the inflatable balloon. The balloon is, instead, inflated using a separate lumen. These ports are used in conjunction with ports more proximally placed to allow passage of blood past a region which is to be treated using the angioplasty balloon.
Target Therapeutics of Fremont, Calif. is the owner by assignment of a number of patents dealing with single lumen low-profile valved balloon catheters. For instance, U.S. Pat. Nos. 5,171,221 and 5,304,198 both to Samson, describe balloon catheters in which a single lumen with a distally placed valve member is used to inflate and deflate the balloon. U.S. Pat. No. 5,437,632, to Engelson, shows a balloon catheter having a number of more proximal segments of varying flexibility.
Other disclosures of distal valve mechanisms used to inflate or deflate a balloon may be found in U.S. Pat. No. 4,848,344 to Sos, et al. (and its reissue, Re 34,633). No distal radially placed infusion orifices may be found in that description.
A similar device is shown in U.S. Pat. No. 5,035,705, to Bums. Burns describes a distal, liquid-tight seal which engages a guidewire. The cooperation between this seal and the guidewire allows inflation and deflation of the balloon.
Another distal valving device is shown in U.S. Pat. No. 5,207,229 to Winters and in 5,454,788 to Walker, et al.
U.S. Pat. No. 4,813,934 to Engleson, et al. and its progeny, U.S. Pat. No. 5,135,494 show another valved balloon catheter having but a single lumen.
A number of catheters which are designed to permit material to exit from the catheter lumen in response to a particular applied pressure are also known. For instance, U.S. Pat. No. 5,250,034 allows such material to exist but has no balloon. Similarly, U.S. Pat. No. 5,267,979 to Appling, permits application of such material. A somewhat similar device is seen in U.S. Pat. No. 5,484,409 except that the device additionally has an expandable balloon which inflates upon application of pressurized fluid as well.
A catheter having no balloon but with a distal atraumatic drug delivery tip potentially with a distally place valve cooperating with a guidewire is found in U.S. Pat. No. 5,380,307, to Chee, et al.
None of the above patents or documents describes a single lumen balloon catheter having a infusion section distal to the catheter and a valve mechanism in the distal end of the catheter assembly.